<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
    </head>
    <body>
        <script>
            let arr1 = [20, 23, 25, 28, 30];
            console.log(arr1);
            for (let i = 0; i < arr1.length/*查询数组的数量，进行定义次数。*/; i++){
                console.log("arr1["+i+"]:"+arr1[i]);
            }
        </script>
    </body>
</html>
